Process of hollow stay-bolt manufacturing



New. 27, 1928.

e. H. MANSFIELD PROCESS OF HOLLOW STAY BOLT MANUFACTURING Original FiledMarch 7, 1925 will: no

INVENTOR Patented Nov. 27, I928.

innate? GEORGE HENRY MANSFIELD, 0F CUYAHOGA FALLS, DHIO.

PROCESS OE HOLLOW STAY-BOLT MANUFACTURING.

Application filed March 7, 1925, Serial No. 13,909. Renewed February 3,1928.

This invention relates to the use'of a new principle in the process .ofrolling hollow staybolt or other iron hollow bars and has for itsobjects the rolling of hollow bars com niercia-lly seamless in structureand considerably more economically than the present practice.

Referring to the accompanying drawings, in Figure L I show a hollow ironpile, consisting of layers of curved sections snugly nested together inthe fashion of a tube with relatively thick wall. Figure 2 shows a tubeor container filled with a refractory material. Figure 3 illustrates themanner of entering the said hollow pile into the rolls of a rollingmill; Figure 4 shows a finished hollow staybolt bar.

In constructing the hollow pile I first arrange two semi-tubularsections 2 together, which constitutes the inner layer of the pile andwhich is then enveloped with outer layers 1. the inner and outer layersso co-arranged that the joints are broken. The hollow pile thus formedis put in a heating furnace and brought to welding heat. Preferably, Ithus heat the pile without inserting any core on the inside, firstbecause it exposes a greater surface which hastens the heating and savesfuel, and secondly because it obviates the subjectionvof a coresubstance to the severe action of the heat. At welding temperature thepile is drawn from the furnace, and a core is inserted into the hollowcenter or hole 7. This core may be a stick of solidified carbon, sand,fireclay, or other refractory material, or may consist of a tubularcontainer 3 filled with sand 4: or other refractory material, plugged atthe ends 5, theplugs held securely by peening over the projecting edges6 of the container 3; and thus in place within the pile as indicated at12 in Figure 3', the hot pile is entered through rolls 8 for the initialreduction pass, which passage through the rolls not only welds the massof incandescent iron into an integral mass but also squeezes in upon thecore holding it securely in place. The pilethus becomes a cored billetand the reduc tion through gradually smaller passes of the rolls iscontinued until the bar is reduced to the proper diameter for hollowstaybolts, as at 9. of Figure 4, with core extremely reduced in crosssection as at 10. In Figure 3 the numerals 11 indicate the collars ofthe rolls 8.

In the case of heating the pile with the core inside, Iprefer to employcarbon. But preferably, I heat the pile first, then after taking out ofthe furnace or approximately at that time, I insert the tube containingthe core, after which the whole is passed through the reducing rolls.Inasmuch as the hot iron starts to chill as soon as drawn from thefurnace, the temperature of it at the time of inserting the core issufliciently low that the core substance is unaffected, reactions of nokind occurring. It is then easier to extract the core from the finishedbar, which may be done by any known method, as drilling, ream- 6 ing, orby using air or water pressure.

' I can also alter the process somewhat 'by using a pierced or drillediron billet instead of the hollow pile, but using the main principlehereof of inserting a relatively cold core into the billet after thelatter has been heated and drawn from the furnace.

It is obvious that other refractory materials may be resorted to andstill remain within the scope hereof, such as graphite, plumbago,siloxicon, lampblack, fireclay, etc.

Having thus described the process what I claim is:

1. The process of making hollow staybolt bars which consists in heatinga hollow billet to rolling temperature, then inserting a re fractorycore in said billet, reducing said billet to the dimensions of stayboltiron, and extracting said core after said reducing operation.

2, The process of making hollow staybolt bars which consists in heatinga hollow billet to rolling temperature, inserting a refractory core insaid billet, rolling said billet to the dimensions of staybolt iron, andextracting said core after said rolling operation.

3. The process of making hollow staybolt bars which consists inproviding a hollow pile composed of a plurality of arcuate sections,heating said pile to welding temperature, then inserting a tubecontainlng refractory material in said pile, rolling said pile to thedimensions of staybolt iron, and extracting said refractory material.

GEORGE HENRY MANSFIELD.

